√8 = √2^2 *2
√2^2 *2 = 2√2
Basically, because 8 equals (2 to the power of 2) times 2, when you find the square root, you can take the 2^2 out, since you're finding the square root of 2 squared.
Hope I kind of make sense.
The answer is B
1cm = 100km
d cm= 135km
d= (135x1)/100
d= 135/100
d= 1.35